Debugger

[dacap]

Create a simple debugger UI for Lua scripts.

A possible solution would be using a VS Code extension:

• https://github.com/satoren/vscode-lrdb
• https://github.com/satoren/LRDB

Or a CLI debugger:

• https://github.com/slembcke/debugger.lua

Check these issues:

• Feature suggestion debugger.lua integration? api#11
• Add debugging support for Lua api#13

[dacap]

I'm doing some work with this one from time to time (while waiting for compilation, etc.).

[dacap]

There is already a minimal working version: https://twitter.com/davidcapello/status/1445174960419442689

I'm still thinking what could be the best approach for the debugger. There are 3 main states for this dialog:

1. Hidden: the Lua debugging hook (lua_sethook) is disabled
2. Visible: the Lua hook is installed but we shouldn't stop in the next executed line (LUA_HOOKLINE), but in case of error the debugger will show the line of the error in context
3. Visible & Running: The Lua hook is installed and we are waiting it to stop/break the execution of the script in some way

When we open the dialog, I think one possible behavior could be this:

1. By default: break on the next executed line, so when we open the dialog, it already starts in the Visible & Running state, like in a "Step In" instruction
2. If the user presses the Pause button: the debugger will not break in the next executed line (only in a breakpoint if there is any configured, or show an error, it's the Visible state)
3. When it's paused, the Play button could show a popup to search the script to start + an option to wait for the next instruction that is executed (e.g. from plugins or dialog callbacks)
4. The breakpoint button should show the list of enabled breakpoints + a list of scripts to open/navigate to add breakpoints, and clicking in some line at the left side of the displayed file should add a new breakpoint in that line.

I forgot to mention: there should be a possibility to view variables/locals and eval expressions.